[sql] Add Dialect.EscapeStruct method (#537)

lib/sql/dialect.go

@@ -8,11 +8,13 @@ import (
 	"strings"
 
 	"github.com/artie-labs/transfer/lib/config/constants"
+	"github.com/artie-labs/transfer/lib/stringutil"
 )
 
 type Dialect interface {
 	NeedsEscaping(identifier string) bool // TODO: Remove this when we escape everything
 	QuoteIdentifier(identifier string) string
+	EscapeStruct(value any) string
 }
 
 type BigQueryDialect struct{}
@@ -24,6 +26,10 @@ func (BigQueryDialect) QuoteIdentifier(identifier string) string {
 	return fmt.Sprintf("`%s`", identifier)
 }
 
+func (BigQueryDialect) EscapeStruct(value any) string {
+	return "JSON" + stringutil.Wrap(value, false)
+}
+
 type MSSQLDialect struct{}
 
 func (MSSQLDialect) NeedsEscaping(_ string) bool { return true }
@@ -32,6 +38,10 @@ func (MSSQLDialect) QuoteIdentifier(identifier string) string {
 	return fmt.Sprintf(`"%s"`, identifier)
 }
 
+func (MSSQLDialect) EscapeStruct(value any) string {
+	panic("not implemented") // We don't currently support backfills for MS SQL.
+}
+
 type RedshiftDialect struct{}
 
 func (RedshiftDialect) NeedsEscaping(_ string) bool { return true }
@@ -41,6 +51,10 @@ func (rd RedshiftDialect) QuoteIdentifier(identifier string) string {
 	return fmt.Sprintf(`"%s"`, strings.ToLower(identifier))
 }
 
+func (RedshiftDialect) EscapeStruct(value any) string {
+	return fmt.Sprintf("JSON_PARSE(%s)", stringutil.Wrap(value, false))
+}
+
 type SnowflakeDialect struct {
 	UppercaseEscNames bool
 }
@@ -75,3 +89,7 @@ func (sd SnowflakeDialect) QuoteIdentifier(identifier string) string {
 
 	return fmt.Sprintf(`"%s"`, identifier)
 }
+
+func (SnowflakeDialect) EscapeStruct(value any) string {
+	return stringutil.Wrap(value, false)
+}

lib/typing/columns/default.go

@@ -23,17 +23,7 @@ func (c *Column) DefaultValue(dialect sql.Dialect, additionalDateFmts []string)
 
 	switch c.KindDetails.Kind {
 	case typing.Struct.Kind, typing.Array.Kind:
-		switch dialect.(type) {
-		case sql.BigQueryDialect:
-			return "JSON" + stringutil.Wrap(c.defaultValue, false), nil
-		case sql.RedshiftDialect:
-			return fmt.Sprintf("JSON_PARSE(%s)", stringutil.Wrap(c.defaultValue, false)), nil
-		case sql.SnowflakeDialect:
-			return stringutil.Wrap(c.defaultValue, false), nil
-		default:
-			// Note that we don't currently support backfills for MS SQL.
-			return nil, fmt.Errorf("not implemented for %v dialect", dialect)
-		}
+		return dialect.EscapeStruct(c.defaultValue), nil
 	case typing.ETime.Kind:
 		if c.KindDetails.ExtendedTimeDetails == nil {
 			return nil, fmt.Errorf("column kind details for extended time is nil")